Field of the Invention
The present invention relates to wireless communications.
Related Art
3GPP (3rd Generation Partnership Project) LTE (Long Term Evolution) that is an advancement of UMTS (Universal Mobile Telecommunication System) is being introduced with 3GPP release 8. In 3GPP LTE, OFDMA (orthogonal frequency division multiple access) is used for downlink, and SC-FDMA (single carrier-frequency division multiple access) is used for uplink. The 3GPP LTE adopts MIMO (multiple input multiple output) having maximum four antennas. Recently, a discussion of 3GPP LTE-A (LTE-Advanced) which is the evolution of the 3GPP LTE is in progress.
As set forth in 3GPP TS 36.211 V10.4.0, the physical channels in 3GPP LTE may be classified into data channels such as PDSCH (physical downlink shared channel) and PUSCH (physical uplink shared channel) and control channels such as PDCCH (physical downlink control channel), PCFICH (physical control format indicator channel), PHICH (physical hybrid-ARQ indicator channel) and PUCCH (physical uplink control channel).
Meanwhile, next-generation mobile communication systems are predicted to add small-sized cells with small coverage and turn-on/off capability and relay nodes to the coverage of a macro cell.
However, adding small-sized cells and relay nodes increases density, thus leading to increased interference. Accordingly, there is, depending on circumstances, a need for restricting (or limiting) the transmission of some uplink physical channels or downlink physical channels in order to mitigate interference.
Meanwhile, the small-sized cells may be required to temporarily turn off or vary for mitigated interference, and this requires system information to be changed. However, there are no conventional efficient procedures to vary system information.